Harold Martin III pleaded guilty to one of 20 counts of willful retention of national defense information.

A former National Security Agency contractor at the center of one of several pending leak cases has pleaded guilty to one of 20 counts he faces for removing classified information from the agency and storing those documents in his home for decades.

Harold Martin III, 52, was arrested in August 2016 and later indicted on 20 counts of willful retention of national defense information. According to the indictment, over the course of 23 years working as a contractor for the intelligence community, Martin took documents from the agencies he was working for and kept them in his Maryland home, some of which included top secret and sensitive compartmented information.

“The indictment alleges that for as long as two decades, Harold Martin flagrantly abused the trust placed in him by the government by stealing documents containing highly classified information,” then-U.S. Attorney Rod Rosenstein, who is now the deputy attorney general, said after Martin was charged.

Martin pleaded guilty to one count of willful retention of national defense information, which carries a maximum of 10 years in prison, followed by three years of supervised release and fines up to $250,000.

However, since the guilty plea did not include a deal of any kind and there are other extenuating circumstances—such as the abuse of a position of public trust and another 19 counts charged in the original indictment—the judge will have additional leeway during sentencing.

Martin won’t be sentenced in relation to this guilty plea until the other 19 counts are resolved.